Offering three-stage warmth technology, Heat Holders Unisex Original Thermal Crew Socks boast a 2.34 Thermal Overall Grade (TOG) rating making them seven times warmer than everyday cotton socks that offer a 0.33 TOG rating. Breathable Heat Holders Yarn provides high-performance insulation to block out the cold, while offering superior moisture-breathing abilities so your feet stay dry. Heat Holders Loops an innovative knitting technology that produces a unique, extra-long-loop cushion pile - hold warm air in. Heat Holders Brushing process maximizes the amount of warm air held inside the socks for continued all-day comfort and warmth. 91% acrylic/5% nylon/3% polyester/1% elastane. One size fits most (fits Mens shoe sizes 7-12; Womens shoe sizes 8-13). Imported. Colors: Black, Charcoal, Denim, Earth Brown (not shown), Forest Green, Navy (not shown), Red, Stonewash, White. Type: Socks.